Point-of-care testing (POCT) is defined as medical testing at or near the site of patient care and has become a critical component of the diagnostic industry. POCT has many advantages over tests in centralized laboratories including small reagent volumes, small size, rapid turnaround time, cost-effectiveness, low power consumption and functional integration of multiple devices. Paper-based POCT sensors are a new alternative technology for fabricating simple, low-cost, portable and disposable analytical devices for clinical diagnosis. The focus of this dissertation was to develop simple, rapid and low cost paper-based POCT sensors with high sensitivity and portability for disease biomarker detection. Lateral flow strips (LFS) were used as the basic platform as it provides several key advantages such as simplicity, fast response time, on site and cost-effectiveness, and it can be used to detect specific substances including small molecules, large proteins and even whole pathogens, in a sample by immunological reactions. Earlier designs of paper strips lacked the quantitative information of the analyte concentration and could only provide single analyte detection at a time. In this study, a series of modifications were made to upgrade the platform to compensate for these limitations. First, we developed a gold nanoparticle based LFS for qualitative colorimetrical detection of bladder cancer related biomarkers in standard solutions and in urine samples. Second, by incorporating an image processing program “ImageJ”, a semi-quantitative LFS platform was established. The capability of the strip was evaluated by testing a small DNA oxidative damage biomarker in urine and cell culture models. Third, we combined the electrochemical method and colorimetrical method for quantitative biomarker detection. Finally, we integrated a commercialized blood glucose meter to quantitatively detection of two non-glucose biomarkers by converting their signals to that of glucose. The upgraded sensor could provide a noninvasive, rapid, visual, quantitative and convenient detection platform for various disease biomarkers. In addition, this platform does not require expensive equipments or trained personnel, deeming it suitable for use as a simple, economical and portable field kit for on-site biomarker monitoring in a variety of clinical settings.

This thesis presents a new mechanical design for an exoskeleton actuator to power the sagittal plane motion in the human hip. The device uses a DC motor to drive a Scotch yoke mechanism and series elasticity to take advantage of the cyclic nature of human gait and to reduce the maximum power and control requirements of the exoskeleton. The Scotch yoke actuator creates a position-dependent transmission that varies between 4:1 and infinity, with the peak transmission ratio aligned to the peak torque periods of the human gait cycle. Simulation results show that both the peak and average motor torque can be reduced using this mechanism, potentially allowing a less powerful motor to be used. Furthermore, the motor never needs to reverse direction even when the hip joint does. Preliminary testing shows the exoskeleton can provide an assistive torque and is capable of accurate position tracking at speeds covering the range of human walking. This thesis provides a detailed analysis of how the dynamic nature of human walking can be leveraged, how the hip actuator was designed, and shows how the exoskeleton performed during preliminary human trials.

Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems can be employed that interpret the natural electric signals produced by the human body as command inputs. One of these novel sensor systems is the myoelectric detection circuit, which can measure electromyographic (EMG) signals produced by contracting muscles through specialized electrodes, and convert the signals into a usable form through an analog circuit. With the goal of making a general-purpose myoelectric detection circuit platform for computer interface applications, several electrical circuit designs were iterated using OrCAD software, manufactured using PCB fabrication techniques, and tested with electrical measurement equipment and in a computer simulation. The analog circuit design culminated in a 1.35” x 0.8” manufactured analog myoelectric detection circuit unit that successfully converts a measured EMG input signal from surface skin electrodes to a clean and usable 0-5 V DC output that seamlessly interfaces with an Arduino Leonardo microcontroller for further signal processing and logic operations. Multiple input channels were combined with a microcontroller to create an EMG interface device that was used to interface with a PC, where simulated mouse cursor movement was controlled through the voluntary EMG signals provided by a user. Functional testing of the interface device was performed, which showed a long battery life of 44.6 hours, and effectiveness in using a PC to type with an on-screen keyboard.

This thesis designed and fabricated various devices that were interfaced to an IC for an active contact lens that notifies the user of an event by detection of an external wireless signal. The contact lens consisted of an embedded antenna providing communication with a 2.4GHz system, as well as inductive charging at an operating frequency of 13.56 MHz. The lens utilized a CBC005 5µAh thin film battery by Cymbet and a manufactured graphene super capacitor as a power source. The custom integrated circuit (IC) was designed using the On Semiconductor CMOS C5 0.6 µm process to manage the battery and drive the display. A transparent, flexible, single cell display was developed utilizing electrochromic ink to indicate to the user of an event. Assembly of the components, encapsulation, and molding were implemented to create the final product. The material properties of the chosen substrate were analyzed for their clearness, flexibility, and biocompatibility to determine its suitability as a contact lens material. Finally, the two different fabrication techniques (microfabrication and screen printing) that were employed to make the devices are compared to determine the favorable process for each part of the system.

No description available.

This paper describes the design, manufacturing, and testing of a novel controllable hypoxic incubator with fully functional oxygen gas control and temperature control in a humid environment. On the current market, a majority of the few hypoxic incubators use pre-mixed gas that does not offer precise control over gas concentration. The objective for this project was to create a chamber that allows the user to set the O2 concentration to varying set points of % O2 while maintaining the chamber at a constant body temperature, CO2 level, humidity, and sterility. To start the project, multiple concepts were developed for the chamber design and the control system. These concepts were compared against developed engineering specs and were evaluated amongst the team and sponsor. From there, a detailed CAD model was developed and utilized to design the structure and was used as a guide for manufacturing. The control system was prototyped on breadboards via Arduino. This breadboard testing served as the map to solder perf boards, which are utilized as the final structure for the control system. Once all parts were sourced, machined, and assembled for the final chamber and the control system, these subassemblies were integrated together with a regulated gas system via various tubing. The integrated final design underwent a variety of testing to validate the incubator design and control system. Testing was performed throughout the course of this project: material testing, gas leak testing, cell test, temperature control test, and gas control system optimization; however, the most important of these tests were those relating to the environmental control of the incubator. These tests confirmed whether the incubator design was functional as a practical incubator. Testing confirmed that O2 and temperature control maintained in spec over a short and long period of time while maintaining a humid environment. CO2 control optimization had more complications than the O2 hypoxia system. During testing CO2 concentration would typically overshoot the set point, likely due to a lack of precise control over the gas flow. CO2 variability was reduced due to optimization in the code, but not fully mitigated. Future iterations of this chamber could improve upon the CO2 control and streamline the user interface.

<p>An electro-optical sensor module was designed to monitor the level of dissolved oxygen (DO) using the method of frequency domain fluoroscopy. Frequency domain fluoroscopy is an optical method that detects the concentration of an analyte by indirectly monitoring the fluorescent lifetime decay. A planar film containing oxygen sensitive fluorophores interacts with a liquid solution, where the percent DO dictates the fluorescent lifetime decay. Amplitude modulated LED emission is created using an electrically implemented oscillator, exciting the oxygen sensitive fluorophores. The emission light from the fluorophores is detected by a photodiode and conditioned. The timing characteristics of the excitation and emission light waveforms are interpreted by a microcontroller. Time delay values have been correlated to actual percent DO values experimentally, and appropriate data modeling has been implemented for calibration purposes. This design is appropriate for application in bioreactors, presenting a functional and cost effective design. Future research can be performed to extrapolate the microcontroller platform to host a pH module, cell number module and glucose module, providing sufficient feedback to an automated bioreactor systems.</p> / Master of Applied Science (MASc)

Heart rate variability (HRV) is a naturally occurring cardiovascular phenomenon referring to the changing timing between consecutive heartbeats. The connection between HRV and overall cardiovascular health and autonomic nervous system function has been well established through prior research and well documented in existing literature. The existing studies, however, included shorter HRV subject recording session, using traditional HRV monitoring methods that do not typically combine electrocardiogram (ECG), seismocardiogram (SCG) and galvanic skin response (GSR) respiration monitoring. The inclusion of longer HRV subject recording may allow for further insight on the possible effects of given observable biological phenomenon on HRV. The current technology for the collection and storage of analog voltage HRV signals exists as separate ECG, SCG and GSR data collection units; all of which are required to make meaningful conclusions about HRV. These individual units work independently from one another, are not portable, must be connected to a power grid at all times, require attachments to the subject at specific body surface locations to ensure data accuracy and require technical expertise to operate efficiently and interpret the obtained data. The study proposes a long-term simultaneous recording device capable of tracking these signals which will allow more detailed inter-signal analysis that can provide more insight into cardiac activity in the presence of changing observable biological phenomena over time.

The collaboration between the School of Engineering and the Department of Physical Therapy at the University of North Florida has introduced the possibility of creating a new environment for pediatric physical therapy assessments. There are currently no methods for remotely monitoring children with impairments. However, with embedded sensor technology in the form of power mobility and accepted therapy assessment tools, remote monitoring can become a possibility. As a part of this work, a ride-on toy car was developed as a remote monitoring device and a case study with a child with a mobility impairment was used as a proof of concept. In this thesis, the background information on the project, the case study diagnosis and history, and the model used to develop this project are detailed.

The contamination of the environment, accidental or intentional, in particular with chemical toxins such as industrial chemicals and chemical warfare agents has increased public fear. There is a critical requirement for the continuous detection of toxins present at very low levels in the environment. Indeed, some ultra-sensitive analytical techniques already exist, for example chromatography and mass spectroscopy, which are approved by the US Environmental Protection Agency for the detection of toxins. However, these techniques are limited to the detection of known toxins. Cellular expression of genomic and proteomic biomarkers in response to toxins allows monitoring of known as well as unknown toxins using Polymerase Chain Reaction and Enzyme Linked Immunosensor Assays. However, these molecular assays allow only the endpoint (extracellular) detection and use labels such as fluorometric, colorimetric and radioactive, which increase chances of uncertainty in detection. Additionally, they are time, labor and cost intensive. These technical limitations are unfavorable towards the development of a biosensor technology for continuous detection of toxins. Federal agencies including the Departments of Homeland Security, Agriculture, Defense and others have urged the development of a detect-to-protect class of advanced biosensors, which enable environmental surveillance of toxins in resource-limited settings. In this study a Surface-Enhanced Raman Spectroscopy (SERS) immunosensor, aka a SERS-linked immunosensor assay (SLISA), has been developed. Colloidal silver nanoparticles (Ag NPs) were used to design a flexible SERS immunosensor. The SLISA proof-of-concept biosensor was validated by the measurement of a dose dependent expression of RAD54 and HSP70 proteins in response to H2O2 and UV. A prototype microchip, best suited for SERS acquisition, was fabricated using an on-chip SLISA to detect RAD54 expression in response to H2O2. A dose-response relationship between H2O2 and RAD54 is established and correlated with EPA databases, which are established for human health risk assessment in the events of chemical exposure. SLISA outperformed ELISA by allowing RISE (rapid, inexpensive, simple and effective) detection of proteins within 2 hours and 3 steps. It did not require any label and provided qualitative information on antigen-antibody binding. SLISA can easily be translated to a portable assay using a handheld Raman spectrometer and it can be used in resource-limited settings. Additionally, this is the first report to deliver Ag NPs using TATHA2, a fusogenic peptide with cell permeability and endosomal rupture release properties, for rapid and high levels of Ag NPs uptake into yeast without significant toxicity, prerequisites for the development of the first intracellular SERS immunosensor.